Variable-speed drive for roll presses



July 4, 1950 H. M. BROWN ET AL VARIABLE SPEED DRIVE FOR ROLL PRESSES Filed April 5, 1949 X M 5 R A Y 0 W E m 8m w Mm mMi T 6 A 0? Z WNW W, M

Patented July 4, 1950 OFFICE VARIABLE-SPEED DRIVE FOR ROLL PRESSES Howard M. Brown, Wood-Ridge, and George Cawlcy, Upper Montclair, N. J.

Application April 5, 1949, Serial No. 85,594

8 Claims. 1

This invention relates to double roll presses for the pressing of plastic and semi-plastic materials and to means for driving the same. In such presses it is customary to drive both rolls of the press. For many applications it is desirable to provide a drive which permits operating the separate rolls of the press at separate angular speeds. It may be dcsiredto operate the two rolls at the same or at variably difierent speeds. If the diameter of the two rolls is not the same, for example as a result of refinishing operations applied unequally thereto, it is necessary to drive the rolls at different angular speeds, if they are to have the same peripheral speed.

Various arrangements have been proposed for providing separately controllable drives to the separate rolls of a press. most of which involve elaborate equipment for interlocking both electrically and mechanically the separate driving means associated with each roll of the press.

We have devised a method and means for driving the separate rolls of a roll press at adjustably different angular speeds which eliminates the necessity for electrical connections between the driving motors associated with the separate rolls of the press and which is simple and inexpensive.

According to our invention, we provide a driving motor for each roll of the press, and we link the rotor of one motor to the stator of the second motor through a variable ratio drive, the stator of the second motor being mounted for rotation with respect to its base.

As the relative rotor-stator speeds of the two motors are constant or substantially constant, the addition of a variable speed to the stator of the second motor produces a variable differential between the speeds of the two rotors to which the rolls of the press are connected.

An embodiment of our invention is shown diagrammatically in the single figure of drawings.

The rolls l and 2 of a roll press are affixed to shafts 3 and 4 journaled at both ends of the'rolls in suitable bearings not shown. The rolls may be made of any suitable material, plastic or rigid, and may be of the same or of dilierent diameters. They may make contact with each other or may be spaced by adistance appropriate to the thickness desired to be imparted to the material passed through the ress.

Afiixed to an end of each of the shafts 3 and 4 are spur gears 5 and 6 to which power is transmitted to turn the rolls.

The driving motor I has a stator 8 fixedly connected to a base 9 and a rotor l connected to the spur gear through a suitable pinion ll. Of

course additional speed changing elements such as the reduction gear unit 26 may be introduced between the rotor [El of the motor 1 and the gear 5. The motor 1 is preferably of a constant speed type, so that within the capacity of the motor the rotor I0 is driven at constant angular speed. Since the stator 8 is fixed to the base, the roll i will therefore also be driven at constant angular speed.

The roll 2 is driven separately from the roll I by a motor 12 having a rotor l3 and stator 14. The stator M is supported at either end in bearings l5 forming part of a base H6. The rotor 13 is supported in suitable bearings, which may be afiixed to the stator M or to the base It, so as to be capable of rotation with respect to the stator I l and to the base It. Power is supplied to the stator [4 by means of slip rings l afiixed thereto. The rotor l3 connects through a speed reducing unit I8 to a pinion l 9 which meshes with the gear 6 of the roll 2.

The stator M has afiixed thereto a toothed ring 20 mounted coaxially with the stator. A pinion 2| is afiixed to a shaft 22 journaled in bearings 23 fixed with respect to the base it. The shaft 22 connects through a suitable speed reducer 24 with an adjustable ratio drive enerally indicated at 25, the other end of which is connected to the rotor if! of the motor 1. In the embodiment illustrated the variable ratio drive consists of a cone and belt drive but it is obvious that other forms of variable speed ratio drive may be used instead.

The motors 1 and I2 establish independently of each other their relative rotor-stator speed. The angular speed of the roll I is determined directly by the speed of the rotor ll} whereas the speed of the roll 2 is determined by the rotor-stator speed of the motor augmented or diminished by the angular speed of its stator M. An angular velocity is imparted to the stator M by the motor 1 operating through the variable ratio drive 25.

The sense of the connection between the stator l4 and a rotor I 0 may be either that which turns the stator H! in the sense of rotation of its own rotor l3 or the reverse. If the sense of rotation of the stator I4 is the same as that of its rotor the angular speed of the roll 2 will be increased by the connection to the motor 1, and vice versa. The speed reducing elements l8 and 24 may be proportioned in any desired manner. By the employment of suitable speed reducing devices as required two rolls I and 2 having a given ratio of diameters may be driven at angular speeds having a variable ratio to each other, according tion, a driving motor connected to one roll, a 1

second driving motor connected to the other roll, a mounting for the stator of the second driving motor permitting the said stator to rotate relative to its base, and variable speed driving means operatively connecting the rotor of the first driving motor with the stator of the second driving motor.

2. A double roll press and drive therefor adapted to turn the separate rolls of the press at adjustably different angular speeds comprising two rolls, means to support the rolls in parallel relation, a constant speed driving motor connected to one roll, a second constant speed driving motor connected to the other roll, a mounting for the stator of the second driving motor permitting the said stator to rotate relative to its base, and variablespeed driving means operatively connecting the rotor of the first driving motor with the stator of the second driving motor.

3. A drive for the rolls of a two-roll press adapted to drive the separate rolls of the press atadjustable speeds, said drive comprising a first constant speed motor having a fixed stator and a rotor operatively connected to one of the rolls of the press, a second constant speed drive motor having a rotatably mounted stator and having a rotor operatively connected to the other roll of the press, and a variable ratio drive operativelyconnecting the rotor of the first drive motor with the stator of the second drive motor.

. 4. A drive for the rolls of a two-roll press adapted to drive the separate rolls of the press at adjustable speeds, said drive comprising a first motor having a fixed stator and a rotor operatively connected to one of the rolls of the press, a second drive motor having a rotatably mounted stator and a rotor operatively connected to the other roll of the press, and a variable ratio drive operatively connecting the rotor of the first drive motor with the stator of the second drive motor. 5. A variable speed drive for the two rolls of a 4 double roll press adapted to drive the said rolls at variable relative speeds, the said drive comprising a first constant speed drive motor having its rotor operatively connected to one of the said rolls, a second constant speed drive motor having its rotor operatively connected to the other of the said rolls, a rotatable mounting for the stator of the second, drive motor,,-a toothedring afiixed to the stator of the second drive motor concentrically therewith, and a variable ratio drive operatively connecting the rotor of the first drive prising a first drive motor having its rotor operatively connected to one of the said rolls, a second drive motor having its rotor operatively connected to the other of the said rolls, a rotatable mounting for the stator or the second drive motor, a toothed ring aifixed to the stator of the second drive motor'concentrically therewith, and a variable ratio drive operatively connecting the rotor of the first drive motor with the said toothed ring. 7. A variable speed drive for the two rolls of a double roll press adapted to drive the said rolls at variable relative speeds, the said drive comprising a first constant speed drive motor having its rotor operatively connected to one of the said rolls, a second constant speed drive motor having its rotor operatively connected to the other of the said rolls, a rotatable mounting for the stator of the second drive motor, and a variable ratio drive operatively connecting the rotor of the first drive motor with the stator of the second drive motor.

8. A variable speed drive for the two rolls of a double roll press adapted to drive the said rolls at variable relative speeds, the said drive comprising a first drive motor having its rotor operatively connected to one of the said rolls, a second drive motor having its rotor operatively connected to the other of the said rolls, a rotatable mounting for. the stator orthe second drive motor, and a variable ratio drive operatively connecting the rotor of the first drive motor with the stator of the second drive motor.

HOWARD M. BROWN. GEORGE CAWLEY.

No references cited. 

